Lens driving device, camera module and camera mounting device

ABSTRACT

The lens driving device is provided with a driving unit for OIS, using the driving force of a voice coil motor to enable an OIS movable unit to swing in a plane orthogonal to the optical axis direction with respect to an OIS fixed unit; the driving unit for OIS comprising a driving unit for AF, using the driving force of the voice coil motor to enable an AF movable unit to move along the optical axis direction with respect to an AF fixed unit; a supporting unit for OIS, formed of an elastomeric material, and having a biaxial hinge structure moveably supporting the OIS movable unit in the plane orthogonal to the optical axis direction; and a supporting unit for AF, formed of an elastomeric material, and having a biaxial hinge structure moveably supporting the AF movable unit along the optical axis direction.

TECHNICAL FIELD

The present invention relates to a shake-correcting lens driving device,a camera module having a shake-correcting function, and a cameramounting device.

BACKGROUND ART

In general, a small-sized camera module is mounted in a mobile terminalsuch as a smartphone. In such a camera module, a lens driving device isemployed (for example, PTL 1). The lens driving device has anauto-focusing function of automatically performing focusing forcapturing a subject (hereinafter referred to as “AF (Auto Focus)function”), and a shake-correcting function (hereinafter referred to as“OIS (Optical Image Stabilization) function”) of optically correctingshake (vibration) upon capturing an image to reduce the irregularitiesof the image.

A lens driving device having the auto-focusing function and theshake-correcting function includes an auto-focusing driving part(hereinafter referred to as “AF driving part”) for moving the lens partin the light axis direction, and a shake-correcting driving part(hereinafter referred to as “OIS driving part”) for swaying the lenspart in a plane orthogonal to the light axis direction.

The AF driving part includes, for example, an auto-focusing coil part(hereinafter referred to as “AF coil part”) disposed at a periphery ofthe lens part, an auto-focusing magnet part (hereinafter referred to as“AF magnet part”) separated from the AF coil part in the radialdirection, and an elastic supporting part (for example, a leaf spring)configured to elastically support an auto-focusing movable part(hereinafter referred to as “AF movable part”) including the lens partand the AF coil part with respect to an auto-focusing fixing part(hereinafter referred to as “AF fixing part”) including the AF magnetpart for example. Automatic focusing is performed by moving the AFmovable part in the light axis direction with respect to the AF fixingpart by utilizing a driving force of a voice coil motor composed of theAF coil part and the AF magnet part. It is to be noted that the AFfixing part may include the AF coil part, and the AF movable part mayinclude the AF magnet part.

The OIS driving part includes, for example, a shake-correcting magnetpart (hereinafter referred to as “OIS magnet part”) disposed in the AFdriving part, a shake-correcting coil part (hereinafter referred to as“OIS coil part”) separated from the OIS magnet part, and a supportingpart configured to support a shake-correcting movable part (hereinafterreferred to as “OIS movable part”) including the AF driving part and theOIS magnet part with respect to a shake-correcting fixing part(hereinafter referred to as “OIS fixing part”) including the OIS coilpart. Shake correction is performed by swaying the OIS movable part in aplane orthogonal to the light axis direction with respect to the OISfixation part by utilizing a driving force of a voice coil motorcomposed of the OIS magnet part and the OIS coil part (so-called barrelshift system). The OIS magnet part can also serve as the AF magnet part,and with such a configuration, the size and the height of the lensdriving device can be reduced. In addition, a suspension wire isemployed as a supporting part for supporting the OIS movable part withrespect to the OIS fixing part, for example.

CITATION LIST Patent Literature PTL 1 Japanese Patent ApplicationLaid-Open No. 2013-24938 SUMMARY OF INVENTION Technical Problem

Preferably, the diameter of the suspension wire is small in view ofincreasing the sensitivity of the OIS driving part (hereinafter referredto as “OIS sensitivity”). When the diameter of the suspension wire issmall, however, the risk of rupture with an impact of dropping or thelike is high. In addition, since the suspension wire is easily deflectedin this case, the OIS movable part cannot be translated (the lens partis tilted), and the tilt characteristics in shake correction aredegraded. The tilt characteristics represent the parallelism of the OISmovable part in shake correction, and the tilt characteristics arerepresented by the inclination angle of the OIS movable part in movementof the lens part. In this manner, when the diameter of the suspensionwire is reduced to increase the OIS sensitivity, the reliability of lensdriving device is sacrificed.

In addition, in the conventional AF driving part, the AF movable part issandwiched by a leaf spring, and as such the structure is complicatedwith a large number of components, and complex assembly work isrequired.

An object of the present invention is to provide a lens driving device,and a camera module and a camera mounting apparatus including the lensdriving device which can provide improved OIS sensitivity and highreliability, and can simplify the assembly work.

Solution to Problem

A lens driving device according an embodiment of the present inventionincludes a shake-correcting driving part including: a shake-correctingmagnet part disposed at a periphery of a lens part; a shake-correctingcoil part disposed separately from the shake-correcting magnet part; anda shake-correcting supporting part configured to support ashake-correcting movable part including the shake-correcting magnet partwith respect to a shake-correcting fixing part including theshake-correcting coil part in a state where the shake-correcting movablepart is separated from the shake-correcting fixing part in a light axisdirection. The shake-correcting driving part performs shake correctionby swaying the shake-correcting movable part with respect to theshake-correcting fixing part in a plane orthogonal to the light axisdirection by use of a driving force of a voice coil motor including theshake-correcting coil part and the shake-correcting magnet part. Theshake-correcting supporting part is made of an elastomer material, andhas a biaxial hinge structure for supporting the shake-correctingmovable part such that the shake-correcting movable part is movable inthe plane orthogonal to the light axis direction. The shake-correctingmovable part includes an auto-focusing driving part, the auto-focusingdriving part including: an auto-focusing coil part disposed at aperiphery of the lens part, an auto-focusing magnet part disposedseparately from the auto-focusing coil part in a radial direction, andan auto-focusing supporting part configured to support an auto-focusingmovable part including the auto-focusing coil part with respect to anauto-focusing fixing part including the auto-focusing magnet part. Theauto-focusing driving part performs automatic focusing by moving theauto-focusing movable part in the light axis direction with respect tothe auto-focusing fixing part by use of a driving force of a voice coilmotor including the auto-focusing coil part and the auto-focusing magnetpart. The auto-focusing supporting part is made of an elastomermaterial, and has a biaxial hinge structure for supporting theauto-focusing movable part such that the auto-focusing movable part ismovable in the light axis direction.

A camera module according an embodiment of the present inventionincludes: the lens part; and the above-mentioned lens driving device.

A camera mounting apparatus according an embodiment of the presentinvention is an information apparatus or a transport apparatus. Thecamera mounting apparatus includes the above-mentioned camera module.

Advantageous Effects of Invention

According to the present invention, the risk of damaging of theshake-correcting supporting part and/or the auto-focusing supportingpart due to dropping impact or the like is remarkably low. In addition,the structure is simple in comparison with conventional structures, andthe number of the components is small. Accordingly, high reliability canbe ensured, and the OIS sensitivity can be increased, while simplifyingthe assembly work.

BRIEF DESCRIPTION OF DRAWINGS

FIGS. 1A and 1B illustrate a smartphone in which a camera moduleaccording to an embodiment of the present invention is mounted;

FIG. 2 is a perspective view of an external appearance of the cameramodule;

FIG. 3 is an exploded perspective view of the camera module;

FIGS. 4A to 4C illustrate a lens driving device as viewed from threesides;

FIG. 5 is an exploded perspective view of the lens driving device;

FIG. 6 is an exploded perspective view of an OIS movable part (AFdriving part);

FIGS. 7A to 7C illustrate states where an AF supporting part and an AFmovable part are mounted;

FIG. 8 is an exploded perspective view of an OIS fixing part;

FIG. 9 illustrates an OIS coil part;

FIGS. 10A and 10B illustrate a relationship between a magnetic fluxgenerated by the OIS coil part and an XY position detection part;

FIGS. 11A and 11B illustrate a bending state of an OIS supporting part(first side supporting member);

FIGS. 12A and 12B illustrate a bending state of an OIS supporting part(second side supporting member);

FIGS. 13A and 13B illustrate a bending state of an AF supporting part(arm);

FIG. 14 is an exploded perspective view of an OIS fixing part accordingof a modification; and

FIGS. 15A and 15B illustrate an automobile as a camera mounting devicein which an in-vehicle camera module is mounted.

DESCRIPTION OF EMBODIMENT

In the following, an embodiment of the present invention is described indetail with reference to the drawings. FIGS. 1A and 1B illustratesmartphone M (camera mounting device) in which camera module A accordingto the embodiment of the present invention is mounted. FIG. 1A is afront view of smartphone M, and FIG. 1B is a rear view of smartphone M.

For example, smartphone M is provided with camera module A as a backside camera OC. Camera module A has an auto-focusing function and ashake-correcting function, and captures an image without image blurringby automatically performing focusing at the time of capturing a subjectand by correcting shake (vibration) at the time of capturing an image.

FIG. 2 is a perspective view of an external appearance of camera moduleA. FIG. 3 is an exploded perspective view of camera module A. Asillustrated in FIGS. 2 and 3, descriptions will be made with anorthogonal coordinate system (X, Y, Z) in the present embodiment. Alsoin the drawings described later, descriptions will be made with anorthogonal coordinate system (X, Y, Z). Camera module A is mounted suchthat the vertical direction (or horizontal direction) is the Xdirection, the horizontal direction (or vertical direction) is the Ydirection, and the front-rear direction is the Z direction at the timeof actually capturing an image with smartphone M. That is, the Zdirection is the light axis direction, the upper side in the drawing isthe light reception side in the light axis direction (also referred toas “macro position side”), and the lower side is the image capturingside in the light axis direction (also referred to as “infinity positionside”). In addition, the X direction and the Y direction orthogonal tothe light axis direction are referred to as “light axis orthogonaldirection.”

Camera module A includes lens part 2 in which a lens is housed in a lensbarrel having a cylindrical shape, AF and OIS lens driving device 1, animage capturing part (not illustrated) that captures a subject imageimaged with lens part 2, cover 3 that covers the entirety, and the like.

As viewed in the light axis direction, cover 3 is a capped squarecylindrical body having a square shape in plan view. Circular opening 3a is formed in the top surface of shield cover 2. Circular opening 3 ais formed in the top surface of shield cover 2. Lens part 2 is exposedto the outside through opening 3 a. Cover 3 is fixed to base 23 of OISfixing part 20 (see FIG. 5) of lens driving device 1. It is to be notedthat cover 3 may be made of a conductive material, and may be groundedthrough OIS fixing part 20.

The image capturing part (not illustrated) includes an image capturingdevice (not illustrated), and is disposed on the image capturing side inthe light axis direction of lens driving device 1, that is, the imagecapturing side in the light axis direction of OIS fixing part 20. Theimaging device (not illustrated) is composed of, for example, a CCD(charge coupled device) image sensor, a CMOS (complementary metal oxidesemiconductor) image sensor, or the like. The image capturing device(not illustrated) captures a subject image imaged with lens part 2.

FIGS. 4A to 4C illustrate the lens driving device as viewed from threesides. FIG. 4A is a plan view, FIG. 4B is a left view, and FIG. 4C is afront view. FIG. 5 is an exploded perspective view of lens drivingdevice 1. As illustrated in FIGS. 4A to 5, lens driving device 1includes OIS movable part 10, OIS fixing part 20, and OIS supportingpart 30 and the like.

OIS movable part 10 includes an OIS magnet part serving as a componentof an OIS voice coil motor, and sways in the plane orthogonal to thelight axis at the time of shake correction. OIS fixing part 20 includesan OIS coil part serving as a component of the OIS voice coil motor, andsupports OIS movable part 10 with OIS supporting part 30. That is, theOIS lens driving part of lens driving device 1 is of a moving magnettype. OIS movable part 10 includes an AF driving part. OIS movable part10 is separated from OIS fixing part 20 such that OIS movable part 10can move in the plane orthogonal to the light axis direction. Here, OISmovable part 10 is disposed on the light reception side relative to OISfixing part 20 in the light axis direction, and separated from OISfixing part 20.

OIS supporting part 30 couples OIS fixing part 20 and OIS movable part10. In the present embodiment, OIS supporting part 30 is composed of alinking member made of an elastomer material (hereinafter referred to as“OIS linking member 30”), not a conventional suspension wire. Anelastomer is a rubber elastic material, and includes a heat curableelastomer (rubber) and a thermoplastic elastomer (elastic plastic).

As illustrated in FIGS. 4A to 5, OIS linking member 30 includes upperframe body 33, first side supporting member 31, and second sidesupporting member 32. It is to be noted that first side supportingmember 31 and second side supporting member are described as “sidesupporting members 31 and 32” in descriptions of their commonconfigurations.

Upper frame member 33 is a frame member having a square shape in planview, and is disposed opposite to base 23 of OIS fixing part 20 in thelight axis direction. Upper frame member 33 is made of a material havinga high rigidity. Upper frame member 33 may be made of a resin materialor a metal material, and preferably, upper frame member 33 is made of aresin material in view of weight reduction. In particular, a liquidcrystal polymer (LCP resin) is favorable as the material of upper framemember 33. With upper frame member 33 made of a liquid crystal polymer,lowering due to the own weight of OIS movable part 10 can be prevented,and favorable tilt characteristics can be ensured while achieving weightreduction.

Side supporting members 31 and 32 are made of an elastomer material.With this configuration, the risk of damaging of side supporting members31 and 32 with a dropping impact or the like is much lower than the casewhere a suspension wire is employed as the OIS supporting part.Accordingly, high reliability can be ensured, and the OIS sensitivity oflens driving device 1 can be increased. In addition, since the primaryresonance of the OIS driving part can be suppressed by utilizing theattenuation force of the elastomer, the application of the damper isunnecessary unlike the case where the suspension wire is employed, andthe assembly work is simplified, and as a result, the productivity isimproved.

Preferably, the elastomer material is a thermoplastic elastomer (forexample, polyester elastomer) which can provide a small spring constantand can allow for injection molding and mass production. A polyesterelastomer has good heat resisting characteristics and good lowtemperature characteristics, and can have a relatively stableflexibility even with temperature change.

Side supporting members 31 and 32 are columnar members having a strengthenough to support OIS movable part 10. Two first side supporting members31 or two second side supporting members 32 are disposed at each of thefour sides of upper frame body 33. It is to be noted that sidesupporting members 31 and 32 may be plate-shaped members that cover theside surfaces of the OIS movable part. Side supporting members 31 and 32have a biaxial hinge structure for bending about two axes so as to allowOIS movable part 10 to translate in the plane orthogonal to the lightaxis.

To be more specific, first side supporting member 31 includes twoY-hinge parts 31 a and 31 b that operate about the Y direction, and thethickness of Y-hinge parts 31 a and 31 b is smaller than that of theportions other than Y-hinge parts 31 a and 31 b in first side supportingmember 31. Here, Y-hinge parts 31 a and 31 b are hinge grooves formed onthe external surface of first side supporting member 31.

The shape of second side supporting member 32 is identical to that offirst side supporting member 31. Specifically, second side supportingmember 32 includes two X-hinge parts 32 a and 32 b extending in the Xdirection, and the thickness of X-hinge parts 32 a and 32 b is smallerthan that of the portions other than X-hinge parts 32 a and 32 b insecond side supporting member 32. Here, X-hinge parts 32 a and 32 b arehinge grooves formed on the external surface of second side supportingmember 32.

Preferably, the hinge grooves of first side supporting member 31 andsecond side supporting member 32 have, but not limited to, an R-shape.With this configuration, the durability against repetitive bending inshake correction is improved.

First side supporting members 31 are suspended from end portions of thetwo sides extending along the Y direction of upper frame body 33. Oneend portion of first side supporting member 31 is fixed to upper framebody 33, and the other end portion of first side supporting member 31 isfixed to OIS movable part 10 (here, magnet holder 121).

Second side supporting members 32 are suspended from end portions of twosides extending along the X direction of upper frame body 33. One endportion of second side supporting member 32 is fixed to upper frame body33, and the other end portion of second side supporting member 32 isfixed to OIS fixing part 20 (here, coil substrate 21).

Upper frame body 33 of OIS linking member 30 is supported by second sidesupporting member 32 over OIS fixing part 20 on the light reception sidein the light axis direction. In addition, OIS movable part 10 issuspended from upper frame body 33 by first side supporting member 31.

Accordingly, when OIS movable part 10 moves in the X direction, onlysecond side supporting members 32 are elastically deformed, and firstside supporting members 31 are not elastically deformed. When OISmovable part 10 moves in the Y direction, only first side supportingmembers 31 are elastically deformed, and second side supporting members32 are not elastically deformed. That is, OIS movable part 10 canselectively move in the X direction and the Y direction.

As described above, OIS supporting part 30 includes upper frame body 33disposed opposite to OIS fixing part 20 in the light axis direction,first side supporting members 31 disposed opposite to each other in theX direction (a first direction orthogonal to the light axis direction),each of which couples upper frame body 33 and OIS movable part 10, andsecond side supporting members 32 disposed opposite to each other in theY direction (a second direction orthogonal to the light axis directionand the first direction), each of which couples upper frame body 33 andOIS fixing part 20. First side supporting member 31 includes two Y-hingeparts, 31 a and 31 b, which are thinner than other portions in firstside supporting member 31 and operate about the Y direction. First sidesupporting member 31 are bent such that the bending directions atY-hinge parts 31 a and 31 b are opposite directions when OIS movablepart 10 moves in the X direction (see FIGS. 11A and 11B). Second sidesupporting member 32 includes two X-hinge parts, 32 a and 32 b, whichare thinner than other portions in second side supporting member 32, andoperate about the X direction. Second side supporting member 32 are bentsuch that the bending directions at X-hinge parts 32 a and 32 b areopposite directions when OIS movable part 10 moves in the Y direction(see FIGS. 12A and 12B).

With OIS supporting part 3030 having the mechanical hinge structureutilizing the elasticity of the elastomer, OIS movable part 10 can bemoved with a small force, and accordingly power saving can be achieved.In addition, the parallelism of OIS movable part 10 is ensured, andaccordingly the tilt characteristics are improved.

FIG. 6 is an exploded perspective view of OIS movable part 10. AFmovable part 11 is disposed radially inside AF fixing part 12 and isseparated from AF fixing part 12. AF movable part 11 is coupled with AFfixing part 12 by AF supporting part 13.

AF movable part 11 includes an AF coil part serving as a component of anAF voice coil motor, and moves in the light axis direction at the timeof focusing. AF fixing part 12 includes an AF magnet part serving as acomponent of the AF voice coil motor, and supports AF movable part 10with AF supporting part 13. That is, the AF driving part of lens drivingdevice 1 is of a moving coil type.

AF movable part 11 includes lens holder 111 and AF coil part 112.

Lens holder 111 is a member having a nearly square shape in plan view,and lens part 2 is fixed to lens housing part 111 a having a cylindricalshape by bonding or screwing. Lens holder 111 includes coil attachingportion 111 b at a side surface along the X direction. Lens holder 111includes link attaching portions 111 c on two side surfaces along the Ydirection. Lens holder 111 includes flange 111 d that protrudes radiallyoutward at the peripheral surface of lens housing part 111 a. Inaddition, sensor substrate 114 provided with position detection part 113(for example, a Hall device) for detecting the position of AF movablepart 11 in the light axis direction is disposed at one surface along theY direction of lens holder 111.

AF coil part 112 is an air-core coil that is energized at the time offocusing, and is wound at coil attaching portion 111 b of lens holder111. The both ends of AF coil part 112 are connected with sensorsubstrate 114. AF coil part 112 has an ellipsoidal shape, and disposedsuch that the coil surface is parallel with the light axis, and in thiscase, AF coil part 112 is disposed such that the XZ surface is the coilsurface. AF coil part 112 faces magnet part 122 (first magnet 122A).

AF supporting part 13 supports AF movable part 11 with respect to AFfixing part 12. In the present embodiment, as with OIS linking member30, AF supporting part 13 is composed of a linking member made of anelastomer material (hereinafter referred to as “AF linking member 13”),not a conventional leaf spring. AF linking member 13 is disposed on aside of lens holder 111, and supports lens holder 111 in a cantileverfashion.

AF linking member 30 includes magnet holder fixing part 131 and two arms132.

Arm 132 has a curved shape along the peripheral surface of lens holderhousing part 111 a. Each arm 132 includes upper arm 132A and lower arm132B. The base end parts (fixed ends) of upper arm 132A and lower arm132B are connected with magnet holder fixing part 131, and areindirectly fixed to AF fixing part 12. Tip end portions (free ends) ofupper arm 132A and lower arm 132B are coupled with each other with lensholder fixing part 132C. A flange housing space is defined with upperarm 132A and lower arm 132B.

Upper arm 132A and lower arm 132B have a biaxial hinge structure that isbent about two axes so as to allow AF movable part 11 to translate. Withthe mechanical hinge structure utilizing the elasticity of theelastomer, AF movable part 11 can be moved with a small force, andaccordingly power saving can be achieved.

To be more specific, upper arm 132A and lower arm 132B include hingeparts 132 a and 132 b which are thinner than other portions in upper arm132A or lower arm 132B and operate about the X direction. Here, hingeparts 132 a and 132 b are hinge grooves formed on the external surfacesof upper arm 132A and lower arm 132B. Preferably, the shape of the hingegroove is, but not limited to, an R-shape.

As described above, AF supporting part 13 includes magnet holder fixingpart 131 (side wall) that is disposed at auto-focusing fixing part 12 ona side of AF movable part 11, and two arms 132 that couple magnet holderfixing part 131 and AF movable part 11 in a cantilever fashion. Each arm132 includes hinge parts 132 a and 132 b which are thinner than otherportions in the arm 132 and operate about in the X direction (light axisdirection orthogonal to direction), and when AF movable part 11 moves inthe light axis direction, arm 132 is bent such that the bendingdirections at hinge parts 132 a and 132 b are opposite directions (seeFIGS. 13A and 13B). With this configuration, the durability againstrepetitive bending in auto focusing is improved.

FIGS. 7A to 7C illustrate states where AF supporting part 13 and AFmovable part 11 are mounted as viewed from three sides. FIG. 7A is aplan view, FIG. 7B is a left view, and FIG. 7C is a front view. Asillustrated in FIGS. 7A to 7C, lens holder 111 is disposed such thatflange part 111 d is located in a flange housing space of arm 132, andlens holder fixing part 132C of AF linking member 13 is fixed to linkattaching portion 111 d.

AF linking member 13 is disposed in the proximity of the side surface oflens holder 111, and thus the size of lens driving device 1 in plan viewcan be reduced, and, AF movable part 11 can be stably supported.

Arm 132 functions as a part for restricting movement of AF movable part11 in the light axis direction. That is, when AF movable part 11 movesto the light reception side in the light axis direction, the top surfaceof flange 111 d makes contact with upper arm 132A, and thus furthermovement thereof is restricted. That is, the distance from flange 111 dto upper arm 132A is the movable range of AF movable part 11 to thelight reception side in the light axis direction. In addition, when AFmovable part 11 moves to the imaging side in the light axis direction,the bottom surface of flange 111 d makes contact with lower arm 132B,and thus further movement thereof is limited. That is, the distance fromflange 111 d to lower arm 132B is the movable range of AF movable part11 to the imaging side in the light axis direction.

As illustrated in FIG. 6, AF fixing part 12 includes magnet holder 121and magnet part 122.

Magnet part 122 includes first magnet 122A and second magnet 122B. Firstmagnet 122A and second magnet 122B are double-sided quadrupole permanentmagnets having cuboid shapes (reference numerals are omitted). That is,in first magnet 122A and second magnet 122B, N pole and S pole equallyappear in the six surfaces. First magnet 122A is disposed along the Xdirection so as to face AF coil part 112. Second magnet 122B is disposedalong the Y direction.

The sizes and positions of AF coil part 122 and first magnet 122A areset such that magnetic fields which are opposite to each other in the Ydirection traverse two long side portions in AF coil part 112. With thisconfiguration, when AF coil part 122 is energized, Lorentz forces of thesame direction in the Z direction are generated at the two long sideportions of AF coil part 122.

As described above, first magnet 122A (AF magnet part) has adouble-sided quadrupole cuboid shape, and is disposed along the Xdirection (the first direction orthogonal to the light axis direction).AF coil part 112 has an ellipsoidal shape, and is disposed such that thecoil surface faces first magnet 122A and that the magnetic fluxes fromfirst magnet 122A intersecting the two long side portions are in theopposite directions. AF supporting part 13 supports AF movable part 11on the opposite side of AF coil part 112.

The AF voice coil motor is composed of first magnet 122A and AF coilpart 112. In addition, the OIS voice coil motor is composed of firstmagnet 122A, second magnet 122B and OIS coil part 211 (see FIGS. 11A and11B). That is, first magnet 122A serves as the AF magnet part and as theOIS magnet part.

First magnet 122A and second magnet 122B are used for detecting theposition of OIS movable part 10 in the plane orthogonal to the lightaxis. In addition, second magnet 122B is used for detecting the positionof AF movable part 11 in the light axis direction.

Magnet holder 121 is a rectangular cylinder member having a space forhousing AF movable part 11 and having a substantially square shape inplan view. Magnet holder 121 includes magnet housing part 121 a at onesurface along the X direction, and magnet housing part 121 b at onesurface along the Y direction. First magnet 122A is disposed in magnethousing part 121 a, and second magnet 122B is disposed in magnet housingpart 121 b.

Magnet holder 121 includes AF link fixing part 121 c at the othersurface along the X direction. Magnet holder fixing part 131 of AFlinking member 13 is fixed to AF link fixing part 121 c.

Magnet holder 121 includes OIS link fixing parts 121 d at the endportions (four portions) of the two sides along the Y direction. Firstside supporting members 31 of OIS linking member 30 are fixed at OISlink fixing parts 121 d.

FIG. 8 is an exploded perspective view of OIS fixing part 20. Asillustrated in FIG. 8, OIS fixing part 20 includes coil substrate 21,sensor substrate 22, base 23 and the like.

In plan view, coil substrate 21 has a square shape, and has circularopening 21 a at a center portion. Coil substrate 21 includes OIS coilpart 211 at a position facing magnet part 122 in the light axisdirection. OIS coil part 211 includes first OIS coil 211A and second OIScoil 211B corresponding to first magnet 122A and second magnet 122B.First OIS coil 211A has an ellipsoidal shape, and is disposed such thatthe coil surface thereof faces the imaging side surface of first magnet122A in the light axis direction and that the magnetic fluxes from firstmagnet 122A intersecting the two long side portions are in the oppositedirections. Second OIS coil 122B has an ellipsoidal shape, and isdisposed such that the coil surface thereof faces the imaging sidesurface of second magnet 122B in the light axis direction and that themagnetic fluxes from second magnet 122B intersecting the two long sideportions are in the opposite directions.

The sizes and positions of OIS coil part 211 and magnet part 122 are setsuch that magnetic fields opposite to each other in the Z directiontraverse the two long side portions of each OIS coil 211. With thisconfiguration, when OIS coil part 211 is energized, Lorentz forces inthe same direction in the X direction or the Y direction are generatedat the two long side portions of OIS coil part 211.

As with coil substrate 21, sensor substrate 22 has a square shape inplan view, and has circular opening 22 a at a center portion. Sensorsubstrate 22 includes a power-source line (not illustrated) for feedingpower to AF coil part 112, OIS coil part 211, and position detectionpart 24, a signal line (not illustrated) for a detection signal outputfrom position detection part 24, and the like.

Position detection parts 24 are mounted on sensor substrate 22. Eachposition detection part 24 is, for example, a Hall device (hereinafterreferred to as “Hall device 24”) for detecting a magnetic field byutilizing Hall effect. Hall devices 24 are disposed at approximatecenters of adjacent two sides of sensor substrate 22. By detecting themagnetic field mainly formed by magnet part 122 with Hall device 24, theposition of OIS movable part 10 in the plane orthogonal to the lightaxis can be specified. It is to be noted that a position detectingmagnet may be disposed independently of magnet part 122 in OIS movablepart 10.

As with coil substrate 21, base 23 has a square shape in plan view, andhas circular opening 23 a at a center portion. Base 23 includes uprightwall 23 b at the periphery of opening 23 a. With upright wall 23 b, coilsubstrate 21 and sensor substrate 22 are positioned with respect to base23.

Here, as illustrated in FIG. 9, first OIS coil 211A and second OIS coil211B have a two-layer structure including elliptical upper coil layer211 a (first coil layer) and lower coil layer 211 b (second coil layer)obtained by dividing upper coil layer 211 a into two parts in thelongitudinal direction. Upper coil layer 211 a and lower coil layer 211b are formed of, for example, one winding, and the current flowdirections thereof are identical. It is to be noted that upper coillayer 211 a and lower coil layer 211 b may be formed of differentwindings. In this case, the windings are provided such that the currentflow directions thereof are identical. Hall device 24 is disposed at aposition corresponding to a portion where lower coil layer 211 b isdivided. The “position corresponding to a portion where lower coil layer211 b is divided” may not only be a position in the divided part, butalso be a position shifted from the divided part in the light axisdirection.

As illustrated in FIGS. 10A and 10B, when current I flows through uppercoil layer 211 a and lower coil layer 211 b in the direction indicatedby the arrow, magnetic field B1 generated by upper coil layer 211 atraverses Hall device 24 from the lower side to the upper side.Meanwhile, magnetic field B2 generated by lower coil layer 211 btraverses Hall device 24 from the upper side to the lower side.Accordingly, the magnetic fields generated by upper coil layer 211 a andlower coil layer 211 b around Hall device 24 are offset.

With this configuration, at the time of energization of OIS coil part211, even when a magnetic flux is generated by OIS coil part 211, themagnetic flux that enters Hall device 24 is small, and thus theinfluence of the magnetic field of OIS coil part 211 on Hall device 24is suppressed. That is, electrical resonance is suppressed, and further,even when a feedback-control is performed at 150 to 200 Hz, the gain inthe low frequency band is improved. Accordingly, the detectionsensitivity of Hall device 24 is improved, and the settling time of theOIS driving part is shortened, improving the shake correction accuracy.

In addition, since upper coil layer 211 a is not divided, the Lorentzforce generated at OIS coil part 211 is large in comparison with astructure in which the entirety of OIS coil part 211 is divided. Thatis, the sensitivity of shake correction is improved.

In lens driving device 1, when OIS coil part 211 is energized, a Lorentzforce is generated at OIS coil part 211 by interaction between themagnetic field of magnet part 122 and the current flowing through OIScoil part 211 (Fleming's left hand rule). The direction of the Lorentzforce is the direction (the Y direction or the X direction) orthogonalto the direction of the magnetic field (the Z direction) and to thedirection of the current flowing through the long side portion of OIScoil part 211 (the X direction or the Y direction).

Since OIS coil part 211 is fixed, a reactive force acts on magnet part122. With this reactive force serving as the driving force of the OISvoice coil motor, OIS movable part 10 including magnet part 122 sways inthe XY plane, and thus shake correction is performed. To be morespecific, the energization current of shake-correcting coil part 211 iscontrolled based on a detection signal representing an angular shakefrom a shake detection part (such as a gyro sensor, not illustrated) soas to offset the angular shake of camera module A. At this time, thetranslation movement of OIS movable part 10 can be correctly controlledby feeding back the detection result of position detection part 24.

When a force in the X direction acts on OIS movable part 10 as a resultof energization of OIS coil part 211 in the manner illustrated in FIG.11A, first side supporting members 31 of OIS linking member 30 are bentas illustrated in FIG. 11B. Specifically, as illustrated in FIG. 11B,the portion of first side supporting member 31 on the lower side ofY-hinge part 31 b moves in the X direction together with OIS movablepart 10 (magnet holder 121), while the portion on the upper side ofY-hinge part 31 a, which is indirectly connected with OIS fixing part 20through upper frame body 33 and second side supporting member 32, doesnot move. That is, first side supporting member 31 is bent such that thebending directions of Y-hinge parts 31 a and 31 b are oppositedirections.

On the other hand, when a force in the Y direction acts on OIS movablepart 10 as a result of energization of OIS coil part 211 in the mannerillustrated in FIG. 12A, second side supporting member 32 of OIS linkingmember 30 is bent as illustrated in FIG. 11B. Specifically, the portionof second side supporting member 32 on the upper side of X-hinge part 32a moves in the Y direction together with OIS movable part 10 (magnetholder 121), while the portion on the lower side of X-hinge part 32 b,which is connected with base 23 of OIS fixing part 20, does not move.That is, second side supporting member 32 is bent such that the bendingdirections of X-hinge parts 32 a and 32 b are opposite directions.

In addition, in lens driving device 1, when AF coil part 112 isenergized, a Lorentz force is generated at AF coil part 112 byinteraction between the magnetic field of first magnet part 122A and thecurrent flowing through AF coil part 112. The direction of the Lorentzforce is a direction (the Z direction) orthogonal to the direction ofthe magnetic field (the Y direction) and to the direction of the currentflowing through the AF coil part 112 (the X direction). With this forceserving as the driving force of the AF voice coil motor, AF movable part11 including AF coil part 112 moves in the light axis direction, andthus focusing is performed. The focusing position is adjusted byanalyzing multiple pieces of image information acquired by an imagecapturing part (not illustrated) while moving AF movable part 11, and byconducting a contrast evaluation, for example.

It is to be noted that, in a non-energization state where focusing isnot performed, AF movable part 11 is kept suspended between the infinityposition and the macro position with AF linking member 13 (hereinafterreferred to as “reference state”), for example. That is, in OIS movablepart 10, AF movable part 11 (lens holder 111) is supported such that AFmovable part 11 is displaceable in the Z direction in the state wherethe position of AF movable part 11 with respect to AF fixing part 12(magnet holder 121) is set by AF linking member 13. At the time offocusing, the direction of the current is controlled based on whether AFmovable part 11 is moved toward the macro position side or toward theinfinity position side from the reference state. In addition, the valueof the current is controlled based on the movement length of AF movablepart 11.

When a force in the Z direction acts on AF movable part 11 as a resultof energization of AF coil part 112 in the manner illustrated in FIG.13A, arm 132 of AF linking member 13 is bent as illustrated in FIG. 13B.Specifically, as illustrated in FIG. 13B, the portion of arm 132 on theleft side of hinge part 132 b moves in the Z direction together with AFmovable part 11, while the portion on the right side of hinge part 132a, which is connected with AF fixing part 12 through magnet holderfixing part 131, does not move. Accordingly, arm 132 is bent such thatthe bending directions of hinge parts 132 a and 132 b are oppositedirections.

As described above, lens driving device 1 includes a shake-correctingdriving part including magnet part 122 (shake-correcting magnet part)disposed at the periphery of lens part 2, OIS coil part 211(shake-correcting coil part) disposed separately from magnet part 122,and OIS supporting part 30 (shake-correcting supporting part) thatsupports OIS movable part 10 including magnet part 122 (shake-correctingmovable part) such that OIS movable part 10 (shake-correcting movablepart) including magnet part 122 is separated from OIS fixing part 20(shake-correcting fixing part) including OIS coil part 211 in the lightaxis direction, and the shake-correcting driving part performs shakecorrection by swaying OIS movable part 10 with respect to OIS fixingpart 20 in the plane orthogonal to the light axis direction by use of adriving force a voice coil motor composed of OIS coil part 211 andmagnet part 122. OIS movable part 10 includes an auto-focusing drivingpart including AF coil part 112 (auto-focusing coil part) disposed atthe periphery of lens part 2, first magnet 122A (auto-focusing magnetpart) disposed separately from AF coil part 112 in the radial direction,and AF supporting part 13 (auto-focusing supporting part) that supportsAF movable part 11 (auto-focusing movable part) including AF coil part112 with respect to AF fixing part 12 (auto-focusing fixing part)including first magnet 122A, and the auto-focusing driving part performsautomatic focusing by moving AF movable part 11 in the light axisdirection with respect to AF fixing part 12 by use of a driving force ofa voice coil motor composed of AF coil part 112 and first magnet 122A.OIS supporting part 30 is made of an elastomer material, and has abiaxial hinge structure for supporting OIS movable part 10 such that OISmovable part 10 is movable in the plane orthogonal to the light axis. AFsupporting part 13 is made of an elastomer material, and has a biaxialhinge structure for supporting AF movable part 11 such that is AFmovable part 11 is movable in the light axis direction.

With lens driving device 1, the risk of damaging of OIS supporting part30 and/or AF supporting part 13 due to dropping impact or the like isremarkably low. In addition, in comparison with conventional structures,the structure is simple and the number of the components is small.Accordingly, high reliability can be ensured, and the OIS sensitivitycan be increased, while simplifying the assembly work.

While the invention made by the present inventor has been specificallydescribed based on the preferred embodiments, it is not intended tolimit the present invention to the above-mentioned preferred embodimentsbut the present invention may be further modified within the scope andspirit of the invention defined by the appended claims.

For example, OIS supporting part 30 and AF supporting part 13 are notlimited to the support structure illustrated in the embodiment as longas OIS supporting part 30 and AF supporting part 13 are made of anelastomer material and have a biaxial hinge structure.

In addition, for example, position detection part 24 for detecting theposition of OIS movable part 10 in the plane orthogonal to the lightaxis may be mounted in coil substrate 21 as illustrated in FIG. 14. Inthis case, first OIS coil 211A and second OIS coil 211B are divided inthe longitudinal direction, and, at the dividing portion, a Hall deviceis disposed and fixed by molding. Coil substrate 21 includes apower-source line (not illustrated) for feeding power to AF coil part112, OIS coil part 211, and position detection part 24, a signal line(not illustrated) for a detection signal output from position detectionpart 24, and the like.

Hall device 24 that is mounted in sensor substrate 22 as in theembodiment is packaged (a so-called hole IC). In contrast, in theexample illustrated in FIG. 14, a wiring pattern and a land are formedin coil substrate 21, and Hall device 24 is mounted as a chip, andaccordingly, the height can be reduced in comparison with aconfiguration in which a hole IC is mounted. In addition, when coilsubstrate 21 has a lamination structure, Hall device 24 can be readilyembedded into coil substrate 21, and a complicated wiring pattern can bereadily formed.

While a smartphone serving as a camera-equipped mobile terminal isdescribed in the embodiment as an example of a camera mounting devicehaving camera module A, the present invention is applicable to a cameramounting device serving as an information apparatus or a transportapparatus. The camera mounting device serving as an informationapparatus is an information apparatus including a camera module and acontrol section that processes image information obtained with thecamera module, such as a camera-equipped mobile phone, a note-typepersonal computer, a tablet terminal, a mobile game machine, awebcamera, and a camera-equipped in-vehicle apparatus (for example, arear-view monitor apparatus or a drive recorder apparatus). In addition,the camera mounting device serving as a transport apparatus is atransport apparatus including a camera module and a control section thatprocesses an image obtained with the camera module, such as anautomobile.

FIGS. 12A and 12B illustrate vehicle V serving as a camera mountingdevice in which an in-vehicle camera module vehicle camera (VC) ismounted. FIG. 12A is a front view of vehicle V, and FIG. 12B is a rearperspective view of vehicle V. In vehicle V, camera module A describedin the embodiment is mounted as in-vehicle camera module VC. Asillustrated in FIGS. 12A and 12B, in-vehicle camera module VC isattached to the windshield so as to face the front side, or attached tothe rear gate so as to face the rear side, for example. This in-vehiclecamera module VC is used for a rear-view monitor, a drive recorder,collision-avoidance control, automatic operation control, and the like.

The embodiment disclosed herein is merely an exemplification and shouldnot be considered as limitative. The scope of the present invention isspecified by the following claims, not by the above-mentioneddescription. It should be understood that various modifications,combinations, sub-combinations and alterations may occur depending ondesign requirements and other factors in so far as they are within thescope of the appended claims or the equivalents thereof.

REFERENCE SIGNS LIST

-   1 Lens driving device-   2 Lens part-   3 Cover-   10 OIS movable part (shake-correcting movable part)-   11 AF movable part (auto-focusing movable part)-   111 Lens holder-   112 AF coil part (auto-focusing coil part)-   12 AF fixing part (auto-focusing fixing part)-   121 Magnet holder-   122 Magnet part-   122A First magnet (auto-focusing magnet part, shake-correcting    magnet part)-   122B Second magnet (shake-correcting magnet part)-   13 AF supporting part, AF linking member (shake-correcting    supporting part)-   131 Magnet holder fixing part (side wall)-   132 Arm-   132 a, 132 b Hinge part-   20 OIS fixing part (shake-correcting fixing part)-   21 Coil substrate-   211 OIS coil part-   211A First OIS coil-   211B Second OIS coil-   211 a Upper coil layer (first coil layer)-   211 b Lower coil layer (second coil layer)-   22 Sensor substrate-   23 Base-   24 Position detection part, Hall device-   30 OIS supporting part, OIS linking member (shake-correcting    supporting part)-   31 First side supporting member-   31 a, 31 b Y-hinge part-   32 Second side supporting member-   32 a, 32 b X-hinge part-   33 Upper frame body-   A Camera module-   M Smartphone (camera mounting apparatus)

1. A lens driving device, comprising: a shake-correcting driving part,the shake-correcting driving part including: a shake-correcting magnetpart disposed at a periphery of a lens part; a shake-correcting coilpart disposed separately from the shake-correcting magnet part; and ashake-correcting supporting part configured to support ashake-correcting movable part including the shake-correcting magnet partwith respect to a shake-correcting fixing part including theshake-correcting coil part in a state where the shake-correcting movablepart is separated from the shake-correcting fixing part in a light axisdirection, wherein the shake-correcting driving part performs shakecorrection by swaying the shake-correcting movable part with respect tothe shake-correcting fixing part in a plane orthogonal to the light axisdirection by use of a driving force of a voice coil motor including theshake-correcting coil part and the shake-correcting magnet part, whereinthe shake-correcting supporting part is made of an elastomer material,and has a biaxial hinge structure for supporting the shake-correctingmovable part such that the shake-correcting movable part is movable inthe plane orthogonal to the light axis direction, and wherein theshake-correcting movable part includes an auto-focusing driving part,the auto-focusing driving part including: an auto-focusing coil partdisposed at a periphery of the lens part, an auto-focusing magnet partdisposed separately from the auto-focusing coil part in a radialdirection, and an auto-focusing supporting part configured to support anauto-focusing movable part including the auto-focusing coil part withrespect to an auto-focusing fixing part including the auto-focusingmagnet part, wherein the auto-focusing driving part performs automaticfocusing by moving the auto-focusing movable part in the light axisdirection with respect to the auto-focusing fixing part by use of adriving force of a voice coil motor including the auto-focusing coilpart and the auto-focusing magnet part, and wherein the auto-focusingsupporting part is made of an elastomer material, and has a biaxialhinge structure for supporting the auto-focusing movable part such thatthe auto-focusing movable part is movable in the light axis direction.2. The lens driving device according to claim 1, wherein theshake-correcting supporting part includes: an upper frame body disposedopposite to the shake-correcting fixing part in the light axisdirection, first side supporting members disposed opposite to each otherin a first direction (X direction) orthogonal to the light axisdirection, each of the first side supporting members coupling the upperframe body and the shake-correcting movable part, and second sidesupporting members disposed opposite to each other in a second direction(Y direction) orthogonal to the light axis direction and the firstdirection, each of the second side supporting members coupling the upperframe body and the shake-correcting fixing part; wherein each of thefirst side supporting members includes two Y-hinge parts which arethinner than other portions in the each of the first side supportingmembers and are configured to operate about the second direction, theeach of the first side supporting members being configured to be bentsuch that bending directions at the two Y-hinge parts are oppositedirections when the shake-correcting movable part moves in the firstdirection; and wherein each of the second side supporting membersincludes two X-hinge parts which are thinner than other portions in theeach of the second side supporting members and are configured to operateabout the first direction, the each of the second side supportingmembers being configured to be bent such that bending directions at thetwo X-hinge parts are opposite directions when the shake-correctingmovable part moves in the second direction.
 3. The lens driving deviceaccording to claim 2, wherein the first side supporting members and thesecond side supporting members are columnar members suspended from theupper frame body.
 4. The lens driving device according to claim 3,wherein the upper frame body has a rectangular shape in plan view;wherein the first side supporting members are formed at end portions oftwo sides of the upper frame body, the two sides being opposite to eachother in the first direction; and wherein the second side supportingmembers are formed at end portions of the other two sides of the upperframe body, the other two sides being opposite to each other in thesecond direction.
 5. The lens driving device according to claim 1,wherein the auto-focusing supporting part includes: a side wall disposedat the auto-focusing fixing part on a side of the auto-focusing movablepart, and two arms configured to couple the side wall and theauto-focusing movable part in a cantilever fashion; and wherein each ofthe two arms includes two hinge parts which are thinner than otherportions in the each of the two arms and are configured to operate abouta direction orthogonal to the light axis direction, the each of the twoarms being configured to be bent such that bending directions at the twohinge parts are opposite directions when the auto-focusing movable partmoves in the light axis direction.
 6. The lens driving device accordingto claim 1, wherein the auto-focusing magnet part has a double-sidedquadrupole cuboid shape, and is disposed along a first directionorthogonal to the light axis direction; wherein the auto-focusing coilpart has an ellipsoidal shape, and is disposed such that a coil surfaceof the auto-focusing coil part is opposite to the auto-focusing magnetpart and that magnetic fluxes from the auto-focusing magnet intersectingtwo long side portions of the auto-focusing coil part are in oppositedirections; and wherein the auto-focusing supporting part supports theauto-focusing movable part on a side opposite to the auto-focusing coilpart.
 7. The lens driving device according to claim 6, wherein theshake-correcting magnet part includes: a first shake correction magnetincluding the auto-focusing magnet part, and a second shake correctionmagnet having a structure similar to a structure of the first shakecorrection magnet, and disposed along a second direction orthogonal tothe light axis direction and the first direction; wherein theshake-correcting coil part includes a first shake correction coil and asecond shake correction coil corresponding to the first shake correctionmagnet and the second shake correction magnet; wherein the first shakecorrection coil has an ellipsoidal shape, and is disposed such that acoil surface of the first shake correction coil is opposite to a surfaceof the first shake correction magnet on an imaging side in the lightaxis direction and that magnetic fluxes from the auto-focusing magnetintersecting two long side portions of the first shake correction coilare in opposite directions; and wherein the second shake correction coilhas an ellipsoidal shape, and is disposed such that a coil surface ofthe second shake correction coil is opposite to a surface of the secondshake correction magnet on the imaging side in the light axis directionand that magnetic fluxes from the auto-focusing magnet intersecting twolong side portions of the second shake correction coil are in oppositedirections.
 8. A camera module, comprising: the lens part; and the lensdriving device according to claim
 1. 9. A camera mounting apparatus thatis an information apparatus or a transport apparatus, wherein the cameramounting apparatus comprises the camera module according to claim 8.